num = eval(input())
str1 = input()
for i in range(0,len(str1)):
    if ord(str1[i]) >= 65 and ord(str1[i]) <= 90:
        if ord(str1[i]) + num > 90:
            print(chr((ord(str1[i]) + num-65) % 26 + 65),end = '')
        else:
            print(chr(ord(str1[i]) + num),end = '')
    elif ord(str1[i]) >= 97 and ord(str1[i]) <= 122:
        if ord(str1[i]) + num > 122:
            print(chr((ord(str1[i]) + num-97) % 26 + 97),end = '')
        else:
            print(chr(ord(str1[i]) + num),end = '')
    else:
        print(str1[i],end = '')
print()